IceCube, currently under construction in the glacial ice at
the geographic South Pole, will be the first neutrino telescope
comprising a volume of one cubic kilometer. At the moment 90% of
the detector has been completed and three quarters are already
taking data while the full detector will be finished in the
austral summer of 2010/11. The search for neutrinos of
astrophysical origin is among the primary goals of the IceCube
neutrino telescope. Source candidates include galactic objects
like supernova remnants as well as extragalactic objects like
active galactic nuclei and gamma-ray bursts. An overview of the
project with special emphasis on results of searches for GRBs
and other transient sources is given. Online neutrino candidate
selection combined with fast reconstruction algorithms allows
IceCube to trigger a network of optical telescopes, which then
search for a possible electromagnetic counterpart. The four
ROTSE telescopes perform the optical follow-up of IceCube
triggers since end of 2008. The program is optimized for the
detection of neutrinos produced in supernovae with mildly
relativistic jets. The performance and sensitivity including
preliminary results of IceCube's optical follow-up program
will be presented.